1. Field of the Invention
This invention relates to a method of removing objectionable flavors and odors from a textured soy protein, wherein the deodorizing treatments may be effected in a relatively facile and economic way on a commercial scale.
2. Description of the Prior Art
Nowadays, the demand for soy protein material is growing in association with resource problems on protein foods. It is well known that a soy protein material retains objectionable "green beany" flavors and odors characteristic of soybean, which greatly presents a substantial block to the extension of applications and increase in consumption of the soy protein. Textured soy protein materials are usually shaped as granules or pellets and have been provided principally for use as substitutes for livestock meats. The textured soy protein materials may include those which have previously been processed in such a manner that the unpleasant flavor and ordor characteristic of soybean is at least partially eliminated therefrom. It is known, however, that many, commercially available products of the textured soy protein still reproduce so-called "green beany" flavors and odors to a considerable extent when heated in the conventional cooking procedures. Owing to this drawback, a considerable restriction is imposed on the conventional textured soy protein materials with respect to their extension of applications and increase in consumption.
Various methods have hitherto been proposed to remove the characteristic objectionable flavors and odors from the soybean proteins and various processed soybean products. Yet, there has been provided no satisfactory method for the removal of the objectionable odors which may be operated in an efficient and facile way on a commercial scale.
Under these circumstances, we have closely studied the removal of the characteristic flavors and odors from a textured soy protein and consequently established a practical method satisfactory for this purpose, on the basis of the following discoveries.